Welding and brazing are processes used to join metallic materials by applying heat to create a structural bond at the interface of the two materials.
Brazing is a lower-temperature process where two materials are joined using a third “filler” material. Because the filler bonds at lower temperatures, brazing is generally used for more heat sensitive, thin-wall components.
Metal bonding temperatures can cause damage to sensitive components. This is particularly true of small, sensitive thin-walled structures that may have a thickness of only thousandths of an inch.
Examples of metal bonding processes known in the aerospace industry include Gas Tungsten Arc Welding (GTAW), Micro Plasma Transfer Arc (MPTA), hydrogen torch, and gas metal arc welding (GMAW). However, the heat generated by these bonding processes has damaged components, and the space necessary for safe operation of these processes is not conducive to making repairs in tight or confined areas.
Lasers are the most accurate means to accomplish sensitive welding and brazing operations on small, thin walled components while minimizing heat damage. Lasers accomplish precise, area controlled heating over a reduced “spot size.” “Spot size” refers to a focused area set at a distance from the end of the laser beam that approximates the area (diameter) to which power is to be delivered. A “heat affected zone” is the actual area affected by the application of heat during a metal bonding process.
However, the use of lasers is extremely dangerous, even lethal, thus limiting the settings in which they can be used. Most laser systems known in the art, therefore, are completely enclosed systems primarily restricted to automated robotic operations. Completely enclosed and pre-programmed laser systems are impractical for unique manual repairs on sensitive components used in the aerospace industry.
Completely enclosed and pre-programmed laser systems are impractical for repairs on sensitive components, and it is often desirable to vary the amount of output power to accommodate specific areas of a work piece which may be more sensitive than other areas. Hand-held laser systems, such as those disclosed in U.S. Pat. Nos. 7,012,216 and 4,564,736 made by Honeywell Corporation and General Electric Corporation, respectively, have been developed to provide lasing systems with more output control. However, lasers, although highly effective, are not used in many settings because contact with a misdirected laser is critically dangerous for humans and can destroy objects and components.
For example, NASA has only recently sanctioned the use of lasers in very controlled and restricted settings. NASA had made a determination that the accuracy and benefits of laser welding are not worth the risk of misdirected lasers, even when the lasers were operated by the most highly trained operators. Features such as proximity sensors are known in the art. However, these safety features are only effective if they can be rapidly and efficiently deployed by a user.
There is an unmet need for safety features that enable safe laser welding in an increased number of settings and particularly in confined spaces.
There is a further unmet need for usable bonding technologies which can minimize heat damage to sensitive components, particularly sensitive and thin-walled components used in aerospace technologies.
There is a further unmet need for a hand-held lasing device that allows a user to flexibly redirect the angle of a laser relative to spot size in real time.
There is also an unmet for a handheld laser device which can be used in confined spaces.